Effects of Penetrating Microwave Blanching on the Drying Characteristics, Physicochemical Properties, and Water Migration of Pleurotus eryngii: Observation of Cell Wall Polysaccharides and Microstructure

This study introduces a novel penetrating microwave infrared hot-air rolling-bed dryer for blanching and drying Pleurotus eryngii. We investigated the effects of different penetrating microwave blanching times (0–10 min) on the drying characteristics, physicochemical properties, moisture migration, polysaccharide structure, and microstructure of Pleurotus eryngii. The results showed that PMB significantly altered the enzyme activity, cell wall polysaccharide content, color attributes, texture attributes, drying kinetics, thermal properties, and antioxidant capacity of Pleurotus eryngii. Meanwhile, the PMB altered the moisture distribution and cellular structure of Pleurotus eryngii, reducing the drying time by 16.67–45.24%. Optimal blanching time was identified at 8 min, significantly enhancing total phenols, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) by 11.35%, 45.74%, and 23.68%, respectively, compared to unblanched samples. Microstructural analysis showed that the cellular structure underwent crumpling and cell wall polysaccharides underwent depolymerization and degradation, which altered the texture and drying characteristics of Pleurotus eryngii. This approach marks a great advancement in the edible mushroom processing and storage industry and promotes the development of high-value dried mushroom products.